Quest Diagnostics Data Breach – Investigated by Federman & Sherwood
October 24, 2026 – Federman & Sherwood, a national consumer protection law firm, is investigating a potential data breach involving Quest Diagnostics, one of the nation’s largest diagnostic testing companies, following reports of unauthorized access to a system containing patient information.
According to an October 22, 2026 filing with the U.S. Securities and Exchange Commission (SEC), Quest Diagnostics discovered unauthorized access to its Quantum Lab Services Manager (LSM) system on October 21, 2026. The system is used by certain healthcare clients to place laboratory test orders and access patient test results.
Quest Diagnostics indicated that patient information was likely accessed during the incident. However, the number of affected individuals and the specific categories of information compromised have not yet been determined.
Following the discovery, Quest Diagnostics initiated an investigation, engaged third-party cybersecurity experts, notified federal law enforcement, and temporarily suspended access to the affected system. The company reported that its overall business operations and ability to serve patients remain unaffected.
The potential exposure of laboratory test results and other sensitive patient information raises concerns about medical privacy, identity theft, and the adequacy of cybersecurity protections.
Federman & Sherwood is investigating whether Quest Diagnostics implemented reasonable cybersecurity safeguards to protect patient information and whether additional security measures could have prevented or reduced the impact of the incident.
The potentially compromised information may include:
- Names
- Social Security numbers
- Medical information
- Health insurance information
- Other sensitive information
What is Quest Diagnostics?
Quest Diagnostics is a leading provider of diagnostic information services, including clinical lab testing, molecular and gene-based testing, and health data analytics.
Individuals who believe their information may have been affected by the Quest Diagnostics data breach are encouraged to contact Federman & Sherwood to discuss their potential legal rights.
Phone: 1-800-237-1277 | Email: info@federmanlaw.com